Polyol-based synthesis of hydrophilic magnetite nanoparticles

In this paper, we report direct synthesis of hydrophilic magnetite (Fe3O4) nanoparticles by thermolysis of iron (III) acetylacetonate in four different liquid polyols, e.g., di(ethylene glycol) (DEG), tri(ethylene glycol) (TEG), tetra(ethylene glycol) (TTEG), and poly(ethylene glycol) (PEG) and characterization of the properties relevant to their surface structure and colloidal stability in an aqueous medium. Fe3O4 nanoparticles prepared in the medium DEG or TEG can be well suspended in aqueous solution, while Fe3O4 nanoparticles prepared in TTEG or PEG agglomerate when these nanoparticles are prepared at their refluxing temperature. However, the aqueous stability of the PEG coated particles prepared at 220 degrees C are good due to the increase in amount of surface-adsorbed polyol coating (27 wt %) and associated positive charges (+30 mV). (c) 2010 American Institute of Physics. [doi:10.1063/1.3355898]